High-Frequency Oscillations of a Flame Held by a Bluff Body

Abstract

Experimental data are presented on the occurrence of flame-sustained transverse oscillations in a 2 × 4-in. duct with a V-gutter flameholder. The flame-speed versus flow-velocity field of burner operation was divided into an oscillation region and a nonoscillation region. The boundary line between the two was approximately described by an equation of the form $SuU1.6=const$ where S_u is the laminar flame speed and U is the flow velocity. The oscillation was characterized by the formation of vortexes downstream of the flameholder tips. These vortices distorted the flame front in such a way as to provide the driving force for the oscillation.